The present invention relates to an improved dispenser head and to a fluid dispenser device incorporating such a dispenser head.
For certain types of fluid dispenser device with which it is desired to dispense fluid in the form of a fine spray, it is known to form a spraying profile upstream from the dispenser orifice, the profile generally comprising a swirling chamber fed by one or more swirling channels. Spray devices of those types are nowadays in widespread use in a large number of fields, in particular in pharmacy, perfumery, and cosmetics.
Document EP-0 131 501 discloses a pusher for a spray, in which a cylindrical insert of constant section is inserted into the expulsion channel. The end face of the insert which is perpendicular to the axis of said insert co-operates with the end wall of the expulsion channel to define a spraying profile including a swirling chamber and one or more swirling channels connecting the expulsion channel to said swirling chamber. In the embodiment disclosed in document EP-0 131 501, said spraying profile is formed in the end wall of said expulsion channel, and the end face of the insert is plane.
That type of device can nevertheless present drawbacks in some cases. Thus, in particular for a nasal pusher, it can be desirable to make said pusher with a hemispherical tip. This can give rise to problems during molding, particularly when the volume of the swirling chamber is small. Combining a hemispherical tip with a horizontal spraying profile extending transversely to the longitudinal axis of the head can give rise to problems, particularly concerning the thickness of the end wall of the head. Under such circumstances, one solution lies in reducing the transverse size of the expulsion channel and the insert, and thus the size of the spraying profile. Nevertheless, that gives rise to an increase in the risk of the pusher becoming clogged in said spraying profile.
An object of the present invention is to provide a dispenser head and a fluid dispenser device incorporating such a dispenser head but which do not reproduce the above-mentioned drawbacks.
An object of the invention is thus to provide a dispenser head including a spraying profile and operating in safe and reliable manner even with a dispenser head tip that is hemispherical.
Another object of the present invention is to provide a dispenser head including a spraying profile in which the risk of said spraying profile becoming clogged is diminished.
Another object of the present invention is to provide a dispenser head including a spraying profile which is easily molded without problems concerning quality at the tip of the head, and which enables materials to be used that further reduce the risk of clogging.
The present invention thus provides a dispenser head for a fluid dispenser device, said head comprising an expulsion channel terminating in a dispensing orifice, an insert being placed in said expulsion channel, the downstream end of said insert in the flow direction of the fluid co-operating with the downstream end portion of said expulsion channel to define a spraying profile, said downstream end of said insert and said downstream end portion of said expulsion channel being both frustoconical, forming a frustoconical spraying profile.
Preferably, said spraying profile comprises a swirling chamber and at least one swirling channel, said swirling chamber being directly connected to said dispensing orifice.
Advantageously, at least one swirling channel connects the expulsion channel to said swirling chamber, the channel(s) being formed on the conical portion of the frustoconical spraying profile and said swirling chamber being formed on the top of the truncated cone of the frustoconical spraying profile.
Advantageously, said frustoconical spraying profile is formed by grooves formed in the walls of the expulsion channel, said insert covering said grooves.
Preferably, said insert occupies substantially all of the volume of the expulsion channel so as to define a narrow expulsion channel.
Advantageously, the tip of said head incorporating said dispensing orifice is hemispherical.
The present invention also provides a fluid dispenser device including a dispenser head as defined above.